(a) Field of the invention
This invention relates to 2- (4- pyridylaminomethyl)-benzimidazole derivatives represented by the following formula: ##STR2## wherein R is a radical selected from the group consisting of hydrogen, short-chain alkyl, short-chain alkoxy, benzoyl, halogenomethyl, halogen, nitro and amino group, and to the preparation thereof.
(b) Description of the prior art
Since benzimidazole derivatives were reported to show antiviral activity by R. L. Thompson [The Journal of Immunology Vol. 55, 345 (1947)], synthesis and biological evaluation of a large number of this series of the compound has been reported. Especially, 2-(anilinomethyl)-benzimidazole represented by the following formula: ##STR3## has been recorded in Chemical Abstracts (Vol. 50, 3906f), and its derivatives have been shown to exhibit biological activity [Mizuno et al; Yakugaku Zasshi: 85, 926-955(1965)]
Picornavirus infections are regarded as the most common viral infections in man. This family of viruses consists of the enteroviruses and rhinoviruses. The enteroviruses cause a broad spectrum of clinical illnesses ranging from eruption, hemorrhagic conjunctivitis and mild upper respiratory ailments to more severe disease such as aseptic meningitis, myocarditis, poliomyelitis, etc. Generally, enterovirus infections of the pediatric population result in greater morbidity and mortality. Recent studies have shown that relatively mild pediatric infections can result in long-term neurological sequelae. Rhinoviruses are responsible for 50% of the common cold infections and cause mild localized infections of the upper respiratory tract.
Since the result of serological testing indicated that there are at least 70 serotypes of rhinovirus and enterovirus, prophylaxis by vaccine has not been practical or effective except for polioviruses. Therefore, chemotherapy against picornavirus infection deserves serious consideration.
In view of above mention, we synthesized 2-(4-pyridylaminomethyl)-benzimidazole and its derivatives, and could demonstrate antipicornavirus activity of these compounds.